In contrast, in "Run on Fat" we show how the ﻿Spanish Ketogenic Mediterranean Diet﻿heavily influenced Preventative Cardiologist Dr Philip Mill's fuelling strategy for Dr Otto Thaning's record breaking British Channel swim. Being 73 years old at the time, Dr Thaning's "health" would have played a much greater role in his performance than an athlete half his age.

Could the fact that the Cape Town heart surgeon felt fantastic after the event be attributed to his carefully planned fat adaptation and fuelling strategy for the 13 hour challenge? That would of course eradicate the frenzy to replenish glycogen stores by any available means in the immediate aftermath of such a monumental physical undertaking.

As a fat adapted endurance athlete, the abilit﻿y to spare glycogen and avoid the deleterious impact of severe depletion (the wall, the bonk) is not just a performance aid. I specifically asked Dr Thaning what - as a Heart Surgeon - he believed the single most important thing one might do to avoid an encounter with his surgical knife? "Avoiding constant insulin spikes in one's habitual diet"he suggests.

Dr Thaning is a very nice man indeed, but he is not a man you would wish to meet on a professional basis.